Conventional sample analyzers are known which measure a measurement sample prepared by dispensing a sample contained in a sample cup and a reagent contained in a reagent container into a cuvette, and analyze the measurement results (for example, model PAMIA-30, Sysmex Corporation). In this sample analyzer, when interruption request for a reagent registration is issued by operating an interrupt/restart key during an analysis operation, a message indicating that sample dispensing is stopped is displayed on a display unit, and the operation of dispensing the sample in a sample cup into a cuvette is temporarily stopped. If a sample has already been dispensed into a cuvette when the interrupt/restart key is operated, a message indicating that reagent is able to be replaced is displayed on the display unit after dispensing a reagent into this cuvette.
In this sample analyzer, however, a new sample is not able to be measured during reagent replacement because reagent and sample are not able to be dispensed into a cuvette during reagent replacement. On the other hand, there is a sample analyzer capable of performing measurements of a sample while reagent is being replaced; for example, the sample analyzer disclosed in Japanese Patent Laid-Open Publication No. 2000-346851.
In the sample analyzer disclosed in Japanese Patent Laid-Open Publication No. 2000-346851, a plurality of reagent racks holding reagent are able to be removed to supplement or replace reagents during a measuring operation, and reagent information of the reagents held in the reagent racks is able to be updated during a measurement operation. Reagent is disposed overall in a square pattern by a plurality of reagent racks. The dispensing part that dispenses reagent is moved in the X-Y direction above an individual reagent that is to be the dispensing object among the reagents disposed in a square pattern by a plurality of reagent racks, suctions the target reagent, and is subsequently moved above a reagent tank whereupon the suctioned reagent is dispensed into the reaction tank.
However, in the sample analyzer disclosed in Japanese Patent Laid-Open Publication No. 2000-346851, the dispensing part must be moved in the X-Y direction above the individual target reagent among the reagent arranged in a square pattern in order to suction the target reagent that is to be dispensed whenever the dispensing part suctions the target reagent. Accordingly, the dispensing part has a large movement range and the mechanism of the dispensing part is therefore complicated. The size of the overall apparatus is thus increased and the control of the apparatus becomes more complex.